I am for the introduction of NMD, as it removes the possibility of large scale nuclear war. It may lead to China trying to build up its arsenal, but to get to the numbers necessary, it would cost them dear.
Under the ABM treaty of 1972, each side was allowed to establish one ABM system, with the Soviet one being centred on Moscow.
SDI is a far bigger proposition, and it has been rightly noted that it is of little effect against terrorist attacks. But there are other measures to deal with that.
As for the allegation that Bush is a warmonger, and would suddenly one day decide to nuke another nation, it is too ridiculous to pay attention to. Even if he did suddenly lose his mind, there is a procedure to follow, and a nuclear strike that is non-retaliatory requires confirmation by a Cabinet member.
The number of strategic nukes have been reduced, but it is always best to have an insurance policy.